Medical procedures involving the cervical spine, particularly surgery, require correct visualization of the vertebrae during radiography (e.g., X-Ray, fluoroscopy, CT, MRI). Typically, a subject's shoulders obscure the lateral imaging of the cervical vertebrae. It is therefore an objective of the present invention to provide means for positioning the subject's shoulders during radiography that migrate the shoulders out of the line of sight of the lateral image of the cervical vertebrae.
Traditionally, said migration of a subject's shoulders is effected via the following means. One traditional method of migrating the subject's shoulders involves Kurlix Bandages that are wrapped around the forearms or wrists of the subject and pulled upon forcefully during live radiography for the purpose of temporary distal migration of the shoulder structures. This method results in temporary migration of the shoulders and unimpeded radiographic visualization of the cervical vertebral structures. However, this method may also result in injury for example, without limitation, Brachial Plexus injury or insult to the subject's shoulder capsule due to over-application of distal migratory force. Another traditional method of moving the subject's shoulders involves taping down the subject's shoulder's and trapezius muscles for the entirety of the procedure. Using this method, the shoulders migrate for the entirety of the procedure allowing for unimpeded radiographic visualization of the cervical vertebral structures. However, some unintended results of this method includes incidence of, without limitation, sore trapezius, nerve damage, tingling hands, reduced digital sensation, and numbness for the subject upon awakening as a consequence of extended unnatural positioning for the entirety of the procedure.
Currently, almost all anatomic positioning for purposes of radiography is performed with foam, which is radiolucent and sufficient to position and fixate portions of the anatomy for example, without limitation, supporting a raised head or immobilizing the head into a certain position. However, foam is incapable of being utilized to migrate portions of the anatomy for example, without limitation, moving and holding the shoulders. Foam lacks the mechanical rigidity and strength needed to migrate portions of the anatomy and merely compresses when subjected to motive pressure. For purposes of variable migration and placement of portions of the anatomy, it is necessary to utilize a rigid radiolucent structure, as opposed to a soft structure. This is much more difficult than one would suppose. The difficulty lies in the actual manufacture of a rigid radiolucent positioning device that is strong enough and radiolucent enough. An object is radiolucent if it creates little interference with the X-Rays or other types of radiography. Except for various “halo” style radiolucent head positioners designed specifically for the fixation of the head during surgery, as opposed to variable positioning or migration, at present there do not exist means for rigid radiolucent anatomic positioning other than a shoulder pusher.
THE Shoulder Pusher is a rigid radiolucent positioning device utilized for migrating the shoulders. The Shoulder Pusher is a radiolucent U shaped member that is positioned on the shoulders to transmit motive force. However, the structure of this device does not have a method of construction that can accomplish this feat effectively. The difficulty of construction of such a device stems from the occurrence of an artifact, which refers to the obscuration of radiography via structural density. Dense objects cause an opaque shadow during X-ray which obscure a clear view of pertinent structures necessary for diagnostic and intra-operative radiography. Additionally, none of the prior arts which have been cited in reference to the Shoulder Pusher involved any radiolucent function as a pertinent part of their designs. They are all merely simple uniform density arches which shared a simple external appearance to the arch as illustrated in the shoulder pusher. In regards to these prior arts, even if they are constructed from a radiolucent material, they would fail for the same reason the shoulder pusher fails; too much density is generated by the structure. Simply constructing something from radiolucent materials does not render it radiolucent. Furthermore, simply reducing the density of the structures of the shoulder pusher as described does not result in a workable remedy, as it lacks sufficient strength while still directly overlaying the vertebral column.
FIGS. 1A and 1B illustrate an exemplary shoulder pusher 100, in accordance with the prior art. FIG. 1A is a diagrammatic top view, and FIG. 1B is a diagrammatic side view. Shoulder pusher 100 comprises a pair of simple arches 103 of uniform density that are bisected by a pair of simple pusher tubes 105. Pusher tubes 105 are connected by an adjustable connection tube 106. Shoulder pusher 100 provides a means of temporary migration of the shoulders via the hand-held application of bilateral motive force during cervical vertebral radiography for the purpose of obtaining optimized lateral imaging of a subject's cervical vertebral column unimpeded by the unintended imaging of the structures of the subjects shoulders. Arch 103 is permanently attached to pusher tube 105 via a carbon/glue interface 107 at the point of bisection. In that carbon fiber is an essentially brittle material, the thickness and density of arch design are essential for purposes of strength as is the placement of pusher tubes 105 in such a manner as to bisect the circumference of arches 103. In typical use, arches 103 of shoulder pusher are positioned on the subject's shoulders and, when pusher tubes 105 are pushed by an operator, transmit a motive force upon the shoulders, facilitating the transient movement of these structures to visualize an additional two to three vertebrae. Although shoulder pusher 100 actually alleviates some artifact due to a clear view of the cervical vertebral structures via a temporary migration of the shoulders, shoulder pusher 100 concurrently contributes artifact. In fact, surgeons have reported that shoulder pusher 100 actually contributes as much artifact as it alleviates, rendering shoulder pusher 100 a partial, as opposed to complete, improvement over the traditional means of optimization of radiography via migration of the subject's shoulders.
Through study of radiographic views obtained from various surgeons, it has been determined that this artifact originated directly from three specific portions of shoulder pusher 100, resulting in the simultaneous introduction a small yet significant artifact directly in the optimum line of site, even as shoulder pusher 100 alleviated the majority of the artifact caused by the shoulders via migration of the structures of the shoulders. These three causes of artifact are as follows: direct/partial obscuration of the cervical vertebral structures due to line of sight positional overlayment and interference of pusher tube 105 as viewed from the crucial lateral perspective, direct/partial obscuration of the lower vertebral structures by arch 103, and direct/partial obscuration of the critical vertebral structures due to the direct overlayment of carbon/glue interface 107.
In view of the foregoing, there is a need for improved techniques for providing rigid radiolucent anatomic positioning that alleviates line of sight overlayment of the vertebral structures, which reduces or eliminates density artifacts while simultaneously maintaining strength.
Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.